Preparation of boron nitride thin films by microwave plasma enhanced CVD, for semiconductor applications

Thin films of boron nitride (BN) have been deposited on silicon and indium phosphide (InP) substrates at low temperature (≈ 300 °C) using a microwave plasma CVD system. The source material is molten borane-dimethylamine. The vapour was decomposed in a microwave nitrogen and argon plasma. The index of refraction and the thickness of the films have been determined by ellipsometry. FTIR spectroscopy was used for a fast phase identification. The composition was analyzed by X-ray photoelectron spectroscopy (XPS). The electrical properties of the films were evaluated by capacitance-voltage (C-V) measurements of metal/BN/semiconductor (MIS) structures. From these results a minimum interface state density of 3.5 1011 cm−2 eV−1 and a dielectric constant of 5.2 have been deduced.